When I was on active duty in the US Army as a lower-enlisted(E-1 to E-4), we(our basic training class/plt & advanced course) were taught to "shoot to wound" or cause the enemy in combat to tie up 3 soldiers on the "battlefield"( the wounded enemy + 2 "battle buddies").
This seemed hard to swallow way back then & even today in the GWOT it's even more difficult to understand.
As posted in other topics(see LTC Dave Grossman's On Killing On Combat) & the non fiction books; One Perfect Op & American Sniper(by former SEAL Chris Kyle), US troops are bound by US law(s), Articles of War, RoEs(rules of engagement), the Hague Accords, the UCMJ and other factors.
US small arms are not ideal weapon platforms compared to artillery, armor, bombs, Navy ships, etc.
Combat troops(outside of spec ops or maybe snipers in some conditions) do not need to kill. They want to have successful(aka: Zulu 7) outcomes to missions.
The Army(DA's) Judge Advocate General mandates legal issues & the UCMJ.
Their main center & school is in Charlottesville VA(on the UVA campus).